According to police, Parker and a friend tried to rob the pharmacist at gunpoint in May 2009. Investigators said Ersland knocked Parker to the ground with one shot to the head, grabbed a different weapon and fired five more shots into his chest and abdomen.

"A coward is someone who will kill someone when they're done," said Parker's mother, Cleta Jennings. "That's not a hero. The real hero here is Antwun."

Jennings said that while her son did go into the pharmacy with a gun, she believes other people put him up to it.

"I know he was scared to death," she said. "I know Antwun was scared to death when he had to go into that pharmacy not under his own will."

In an exclusive interview with KOCO, Jennings said she was angry when she found out two pathologists with the Oklahoma County Medical Examiner's Office filed conflicting statements, which call the former chief's ruling into question. That ruling could affect the District Attorney's decision to prosecute.

"That man literally shot my son down, had no remorse, went back, got another gun, reloaded it and came back and shot him five more times," Jennings said.

The interim chief said he's still reviewing the case. District Attorney David Prater said he's not prepared to drop the case against Jerome Ersland, but said it is his duty to listen to all evidence that's brought forth in every case.

Jennings said her son will never have a chance to prove his innocence.

"He still should have had a chance to go to court and defend himself," she said. "He's just like everybody else, innocent until proven guilty."

She said she will continue to share his story and remember his achievements as she carries the pain inside her.

"He was not a masked robber. His name was Antwun Parker. He was a human."

She said she may file a civil lawsuit against Ersland if she's not happy with the course of action in the criminal case.